Ed: Keith have you ever seen a chart on the accuracy of Pollsters?
http://farm4.static.flickr.com/3295/252 ... f95a_o.png
Note where CBS / New York Times & Gallup fall in percentage of pollster induced error
Pollster Ratings v4.0: Results
by Nate Silver @ 6:13 PM
-- These ratings reflect polling for President (general and primary elections), U.S. Senate, U.S. House, and gubernatorial races since 1998. More recent cycles are weighted more heavily. This is a truly massive amount of data: roughly 4,700 polls.
-- The variable called rawscore is the most direct measure of a pollster's track record. However, it is much inferior to PIE -- or Pollster-Introduced Error -- for evaluating the effectiveness of different pollsters on a going-forward basis. Because polling involves a great deal of luck in the near-term, rawscores must be substantially regressed toward the mean. However, different types of pollsters are regressed to different means. In particular, pollsters that have made a commitment to transparency and disclosure have been shown to have superior results over the long-run. The way we measure this is whether the pollster was a member of either the NCPP or the AAPOR Transparency Initiative as of 6/1/10.
-- PIE is expressed as a positive number and reflects the amount of error that a pollster introduces above and beyond that which is unavoidable due to things like sampling variance. The lower a firm's PIE the better.